Rhizobium radiobacter peritonitis: the first case report from India and review

Rhizobium radiobacter is an opportunistic human pathogen in debilitated patients with foreign plastic intravascular devices and peritoneal dialysis (PD) catheters. We performed a Medline search of the English-language literature on R. radiobacter continuous ambulatory peritoneal dialysis (CAPD) peritonitis in end-stage renal disease (ESRD) and reviewed 13 cases.

A 54-year-old male with ESRD secondary to chronic long-standing type II diabetes mellitus presented to the nephrology outpatient department with fever, abdominal pain and cloudy PD effluent. The patient was admitted to the hospital. PD fluid was sent for cell count, Gram stain and culture. The white blood cell (WBC) count in the PD fluid was 6400 mm^-3 with 82 % neutrophils. Gram staining of the fluid showed plenty of Gram-negative bacilli. A presumptive diagnosis of CAPD peritonitis was made and empiric intraperitoneal cefazolin and tobramycin were started. The PD fluid culture grew non-fermenting, Gram-negative bacilli identified as R. radiobacter. Empiric antibiotic therapy was continued and the patient's abdominal pain subsided. The peritoneal fluid counts decreased to 50 WBCs mm^-3 on day 4. However, his abdominal pain recurred on day 8 and his PD fluid count increased to 300 cells mm^-3. The catheter was therefore surgically removed.

Although R. radiobacter is considered a contaminant, it can cause relapsing symptomatic peritonitis peritoneal catheter removal.